The present invention relates generally to sealing systems for rotating machines and, more specifically, to an improved sealing assembly used therein.
Sealing systems are often used in machine applications to provide a seal between a rotating shaft and a machine housing, wall or other stationary element of a machine. Such machine applications include, but are not limited to, fluid pumps and fluid mixing machines. The seal may be provided to prevent fluids being worked on, such as a liquid being pumped, from entering either the drive mechanism of the machine or the atmosphere.
These machines generally include a stationary element (such as a housing), a drive element (such as a shaft), and a driven element (such as an impeller) connected to the drive element. One way to provide a rotatable seal between the drive element and the stationary element is by providing two sealing rings and leaf springs. One ring forms a seal with a sealing face that is rigidly attached to the stationary element. The other ring forms a seal with a sealing face that is fixed to the driven part. The two sealing rings are biased against their respective sealing faces by the leaf springs. The resulting seal is actually two rotatable seals placed in series.
One such sealing system is shown and described in U.S. Pat. No. 3,028,163 to Heinrich. Sealing systems having only one rotatable seal are also known. All of these sealing systems are complex and thus inherently prone to failure.